Zu Chongzhi, courtesy name Wenyuan, was a Chinese astronomer, inventor, mathematician, politician, and writer during the Liu Song and Southern Qi dynasties. He was most notable for calculating pi as between 3.1415926 and 3.1415927, a record in precision which would not be surpassed for over 900 years.

Song, known as Liu Song, Former Song (前宋) or Song of (the) Southern dynasties (南朝宋) in historiography, was an imperial dynasty of China and the first of the four Southern dynasties during the Northern and Southern dynasties period. It succeeded the Eastern Jin dynasty and preceded the Southern Qi dynasty.